The only combo really worth having stronger tanking pet in my opinion is Wd/D. I mean if you're gonna have a tank, you have to have heals for that tank. Wd/D has heals down good, even the Elven Prayer skill (which has an elite that adds PDam and MDam to pets) is massively better on Wd/D (when using caster gear) than any other warden. I'm talking about one insta-skill that fully heals your pet due to the heal going through the healing formula.
Really the only thing Wd/D needs to have a meaty survivable tank pet is the elite that (for god knows what reason) Wd/M has: [Tough Oak]. This skill at lvl 70 adds +75% pdef to your Oak, and shortens the Punch CD to 4 seconds.
As a Wd/D, Once I max, I am going to make two sets of gear. One is going to have a lot of stats that can be passed on to pets, mostly focusing on HP/PDef/PAttack stacking, and the other set is going to be my mage DPS set to take advantage of [Earth Spirit Essence] which at lvl 55 with a 2.2kMdam staff does 118 crit white hits (imagine lvl 65+ 6-8k MDam staffs with mage gear:cool

. When I am going to summon my "Tank" Oak, I will swap gear to the HP/PDef/PAttack, buff and summon, then switch back afterwards.
Maybe this way, my Oak can keep aggro and I can take advantage of the bonuses of a magic build on Wd/D. Still, if they increased the taunt modifier on Punch and gave Wd/D the Tough Oak elite, you would see a very viable solo pet class take form.
As it is, my Oak doesn't carry enough over from my mage gear to do ANY tanking at all. I eat the Oak, then summon nature crystal.
PLEASE GIVE WD/D TOUGH OAK AT LEAST. Lol.